The aims of this study were to determine whether a single treatment of estradiol dipropionate (EDP) could induce pseudopregnancy in pigs and to determine the effectiveness of prostaglandin F2α (PGF2α) treatment for oestrus synchronization in EDP-induced pseudopregnant pigs. A high efficiency (84-95%) of pseudopregnancy was achieved with a single treatment of 20 mg EDP 8 and 11 days after ovulation (equivalent to 9-13 days after the onset of oestrus or 7-11 days after the end of oestrus). When PGF2α or its analogue PGF2α-A was administered twice with a 24-h interval 25-35 days after EDP treatment in 84 pseudopregnant female pigs, oestrus after PGF2α treatment was observed in 83 pigs (99%). No significant differences were found in farrowing rate (85.0-100%), average total litter size (10.0-11.4), average born-alive litter size (9.4-10.3), or average piglet birth weight (1.56-1.71 kg) between PGF2α-A-treated pseudopregnant female pigs that were inseminated during synchronised oestrus and females inseminated during spontaneous oestrus on commercial pig farms. These results indicate that a single treatment of EDP during the luteal phase of the oestrus cycle can induce pseudopregnancy in pigs and that oestrus synchronization programs using EDP and PGF2α-A are available as practical and convenient procedures for commercial farms.
(Pathology and Pathophysiology Research Division)
References:
- Noguchi M. et al (2010) J. Reprod. Dev. 56(4):421-427
- Noguchi M. et al (2011) Reprod. Biol. Endocrinol. 9:157
